My characters face is too bumpy
The main problem here is the topology of you mesh, no amount of smoothing will completely fix that. 
You should avoid big changes in face size between neighbouring faces (smoothing will help with this) 
Also try and remove all the faces with more than 4 edges, as these can get triangulated in odd ways when displaying the mesh.
Another thing to avoid is vertices with lots of edges attached to them as these can lead to pinching artifacts with smooth shading and also subdivision.

The general rule for modelling faces is to make face loops around each of major features (e.g. they eyes should have rings of faces around them like goggles). See the following image for an example of a face with good topology (taken from blender.org)

There are a number of tutorials around the net covering best practices for character modelling which would help you, for example:
https://cloud.blender.org/p/blenderella/56040ecf044a2a00a515ada6